> I have been using PDA + calcium carbonate for the screening of acid
>producing fungi, but the outcome was not satisfied. Does anyone have any
>effective method for the screening of acid producing fungi? Where could
>be the possible habitat of the microorganisms?
Many brown-rot wood decay fungi produce "tons" of oxalic acid driving the pH
of decaying wood down below 2.0 in some cases.
There are pH indicator dyes that detect low pH that can be incorporated into
media (assuming they aren't too fungitoxic!). See: Green, F. III, Larsen,
M.J., Winandy, J.E., and Highley, T.L. 1991. Role of oxalic acid in
incipient brown-rot decay. Material und Organismen 26:191-213. If you
can't find this journal, E-mail me your address and I will send you a
reprint.
So why are you looking for acid-producing fungi?
Jessie Micales (jmicales at facstaff.wisc.edu)